Immunophenotypic analysis of bone marrow B lymphocyte precursors (hématogones) by flow cytometry.

The aims of this flow cytometry study were to quantify B lymphoid precursors known as hématogones across age and clinical conditions and to study the immunophenotypic profile of these benign immature B cells. A total of 406 consecutive marrow specimens were analyzed for hématogones using 4-color flow cytometry during a 19 month period (60% males and 40% females). The age range was 3 months to 89 years. Hématogones were present in 80% of the specimens. Morphologic analysis of the smears from each patient showed small numbers of hématogones (<13% of total cellularity). The B cell population was defined by CD19 + CD45 bright positivity, coexpression of other B lineage markers: CD20, CD22, CD10, CD29, CD38 and CD58 in addition to HLA-DR and CD34. In our study we found a significant decline in hématogones with increasing age but a broad range was found at all ages. Marrow from some adults contained relatively high numbers. Diagnosis in these patients included cytopenias, infections, and neoplastic diseases. Distinction of hématogones is critical for disease management particularly after therapy of paediatric B acute lymphoblastic leukaemia to monitor for minimal residual disease.

Identification of the translocation t(15;17) in acute myeloid leukemia (AML) initially classified as FAB M1: case report and review of the literature.

We report a case of a patient aged about 53 years, who initially presented with hematological disorders (WBC: 44000/mm3, Hb: 11g/dl, Pit: 127000/mm3) without tumoral syndrome. The Wright-Giemsa stained bone marrow and peripheral blood smears showed a population of blast cells characterized by cells with high N/C and strongly basophilic cytoplasm without granules. The nuclei were predominantly round. Nuclear chromatin was fine and contained small nucleoli. Cytochemisty was positive for peroxidase activity. Immunophenotyping showed myeloid typical markers of granulocytic lineage (MP0+, CD13+, CD33+, CD117+, CD34-). The karyotype revealed the expression of t(15;17) chromosomal translocation. The diagnosis of acute myeloid leukaemia (AML) was then evoked initially. The cytological features corresponded closely to the M1 subtype as defined in the FAB classification. The patient was treated with induction therapy according to the 7/3 protocol. One month later, he was discharged from hospital on hematological and cytogenetic remission. He died at home because of a heart attack. From the biological findings the patient was retrospectively diagnosed as having promyelocytic leukemia (hyperbasophilic form).

First-line thalidomide-dexamethasone therapy in preparation for autologous stem cell transplantation in young patients (<61 years) with symptomatic multiple myeloma.

Thalidomide-dexamethasone therapy was given in patients (<61 years) with previously untreated symptomatic multiple myeloma. The aim of this study was to assess the efficacy and toxicity of this combination as first-line therapy, and to determine its effect on stem cell collection and engraftment. During first-line therapy, thalidomide and dexamethasone were administered for 75 days (200 mg/day) and 3 months, respectively. The monthly dose of dexamethasone was 20 mg/m2/day for 4 days, with cycles repeated on days 9 to 12 and 17 to 20 on the first and the third month of therapy. After first-line therapy, a collection of peripheral blood stem cells (PBSC) was performed. Between May 2003 and September 2004, 60 patients were included. On an intent-to-treat basis, the overall response (> or =partial response) rate was 74%, including 24% of patients who obtained a complete remission. Grade 3-4 toxicities consisted of infections (12%), deep-vein thrombosis (3%), constipation (5%), and neuropathy (5%). A total of 58 patients (96%) proceeded to PBSC mobilisation and yielded a median number of 8 x 10(6) CD34+ cells/kg. First-line thalidomide-dexamethasone therapy is effective and relatively well tolerated in young patients with symptomatic multiple myeloma. This combination does not affect PBSC mobilisation.

Contribution of flow cytometry to acute leukemia classification in Tunisia.

The precision of immunological characterization of leukemias was improved by a certain number of technical innovations, particularly hybridoma production and standardization, resulting in monoclonal antibodies and definition of recognised cellular antigens (designated by CD: Cluster of Differentiation). The aim of this work was to determine the immunophenotyping profile of patients with leukemia, by means of a flow cytometric method: 66 blood samples coming from leukemic persons in the Sahel region were studied by flow cytometry, using about thirty monoclonal antibodies all marked with a fluorochrome, in one or two colour systems to assess their distribution according to type (lymphoid B or T / myeloid) and age, and to search for possible co-expressions of markers of different lineages. The marked preponderance of childhood B-ALL in our series is, at least partly, attributable to the age distribution of the Tunisian population. In agreement with studies from other countries, the majority of AML cases occurred among adults. A high proportion of AML cases in our series co-expressed markers of other lineages. Overall, accurate classification of acute leukemias was possible from a simple peripheral blood sample in 62 of 66 cases (93.9%).

[Molecular analysis and prenatal diagnosis of beta-thalassemia: about our experience in central Tunisia]. / Analyse moléculaire et diagnostic prénatal de la beta-thalassémie: à propos de notre expérience en Tunisie centrale.

Beta-thalassemia, by its high frequency and its heterogeneity, constitutes a real problem of health in Tunisia. Prenatal diagnosis by DNA analysis represents the only reality for couples at risk. The denaturant gradient (urea and formamide) on polyacrylamide gel electrophoresis has been performed in our laboratory, using psoralen as chemical clamps. This method is simple, reliable, safe, rapid, without radioactivity and has a reasonable cost (chemical clamps). Even if it needs an informatic modelization in other laboratories, this method seems to be adapted to our economic and work conditions and to the molecular heterogeneity of the Tunisian beta-thalassemia. We present the results of an epidemiological molecular study on 75 patients with beta-thalassemia and the results of ten prenatal diagnosis. The molecular lesions codon 39 (C-T) and IVS1 nt2 (T-G) are the most frequent in our study. This technical approach provides genetic counselling for at risk families by offering prenatal diagnosis (reducing as possible the cost and the delay of the result) after prealable family study and identification of the mutation(s).

[Invasive aspergillosis in the leukemic patient]. / Aspergillose invasive chez le leucémique.

Invasive pulmonary aspergillosis (IPA) remains a life threatening complication in immuno-compromised and especially in neutropenic patients. We report our experience in the diagnosis and therapeutic management of IPA in 8 patients with acute leukemia. All patients were neutropenic (PNN < 100/mm3, mean duration = 37 days) when IPA was diagnosed. Clinical signs included fever above 39 degrees and cough in all cases, chest pain in 4 cases, hemoptysis in 3 cases, rales in 5 cases. Chest x ray showed one lesion in 4 cases and multiple lesions in 4 cases. The diagnosis of IPA was established by bronchoalveolar lavage (BAL) in 5 cases, tissue biopsy in one case, positive sputum in one case and it was highly probable in one case. Thoracic computed tomographic (CT) scans were preformed after diagnosis confirmation of IPA and showed one or multiple lesions with air crescent signs. Serological tests were positive in 4 cases late in the course of IPA. All patients were treated with i.v. Amphotericin B. Outcome was favorable in 5 cases and three patients died by massive hemoptysis (in two cases) and systemic aspergillosis (in one case). Early diagnosis and appropriate treatment are essential to improve IPA prognosis.

[Gastric adenocarcinoma secondary to Hodgkin's disease treatment]. / Adenocarcinome gastrique secondaire au traitement d'une maladie de Hodgkin.

UNLABELLED: Second malignant neoplasms are a major cause of late morbidity and mortality following treatment for Hodgkin's disease. Gastric carcinoma belong to the rare secondary malignancies induced by radiation-therapy and it is associated with a poor prognosis. We report a patient treated for Hodgkin's disease by 6 ABVD and total lymphoid radiation therapy, who developed a gastric carcinoma 9 years after completing treatment. Our case fits the criteria for radiation induced malignancies reported from the literature: IN CONCLUSION: recommendations are presented for both prevention and early detection of the tumours we recommend a strict follow-up for patients treated for HD to detect second cancers.

FIP1L1-PDGFRA positive chronic eosinophilic leukemia in Tunisian patients.

Hypereosinophilic syndromes (HES) are a heterogenous group of rare disorders characterized by sustained and otherwise unexplained overproduction of eosinophils with organ involvement and consecutive dysfunction. Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion in HES supports the diagnosis of chronic eosinophilic leukemia (CEL) and provides a molecular explanation for the pathogenesis of this disorder. We screened seven Tunisian patients fulfilling the WHO criteria of HES for the presence of the FIP1L1-PDGFRA fusion gene using nested reverse transcription polymerase chain reaction on peripheral blood samples. Four of the seven patients were positive for this fusion gene. Sequence analysis revealed a substantial heterogeneity of the fusion transcripts due to the involvement of several FIP1L1 exons. All patients were male. The median age at diagnosis was 24 years (range, 18-50); one patient had a history of hypereosinophilia of more than 10 years. Two patients had clinically important and symptomatic eosinophilic endomyocardial disease with thrombotic events. Splenomegaly was constant in FIP1L1-PDGFRA positive CEL but not in the other HES patients (only 1/3).

[Acquired amegakaryocytic thrombocytopenic purpura treated with intravenous immunoglobulins]. / Le purpura thrombopénique amégacaryocytaire acquis traité par des immunoglobulines intraveineuses.

Acquired amegakaryocytic thrombocytopenic purpura is a rare disorder characterized by severe thrombocytopenia due to the absence of bone marrow megakaryocytes. The pathogenic mechanisms of this disorder have not well defined; consequently, several empirical therapies are used. We reported the case of a 38-year-old mean who was hospitalized for serious bleeding syndrome. The platelet count was 10 yen10(9)/L. The bone marrow aspirate and biopsy showed the absence of megakaryocytes but otherwise normal granulocyte and erythroid precursors. No definable etiology has been found. After the unsuccessful use of prednisone, intravenous immunoglobulin therapy was started and resulted in favorable reponse.